As is known in the art, there are a variety of examples of slide apparatuses. FIG. 1 is a vertical cross-sectional view illustrating a slide apparatus disclosed in Korean Laid-Open Patent Publication No. 10-2010-0079712 filed by the applicant. A slide 1 includes a fixed rail 2, a first movable rail 3, a second movable rail 4, and a ball retainer 100. The ball retainer 100 is situated between the fixed rail 2 and the first movable and between the first movable rail 3 and the second movable rail 4. A plurality of balls 9 are accommodated in the ball retainer 100. The fixed rail 2 is fixed to a fixed part, such as a desk, a cabinet, or the like, and the second movable rail 4 is fixed to a movable part, such as a drawer. The first movable rail 3 slides with respect to the fixed rail 2. Since the second movable rail 4 slides with respect to the first movable rail 3, the movable part can be retracted into and withdrawn from the fixed part. The plurality of balls 9 positioned between a raceway 8 of the second movable rail 4 and a raceway 7 of the first movable rail 3 and between a raceway 5 of the fixed rail and a raceway 6 of the first movable rail 3 roll when the second movable rail 4 slides with respect to the first movable rail 3 and the first movable rail 3 slides with respect to the fixed rail. In this manner, the plurality of balls 9 reduce the friction between rails during the sliding of the first movable rail 3 and the second movable rail 4 while supporting the load of the movable part. The ball retainer 100 serves to maintain the distances between the balls 9 such that the load can be properly transferred between the rails.
Typically, the balls 9 accommodated in the ball retainer 100 are formed of a metal in order to support the load of the drawer. The body of the ball retainer 100 is formed of a metal or a plastic having a suitable strength.
In the process of withdrawing and retracting the drawer, vibrations and force are applied to the drawer. Since the drawer to which the slide apparatus 1 is mounted is generally fabricated of wood, such vibrations and force may form dust or may cause wood chips to be detached from the drawer and the desk. In this case, when dust or the like falls on the raceways 5, 6, 7, and 8 of the rails 2, 3, and 4, the rolling operation of the balls 9 may be hindered. In other words, when dust or the like is accumulated on portions of the raceways 5, 6, 7, and 8 on which the balls 9 move, dust or the like sticks to the balls 9. This consequently hinders the rolling movement of the balls 9, whereby the balls 9 do not smoothly roll. When the drawer is withdrawn or retracted, noise occurs, thereby causing discomfort to a user.
In addition, lubricant such as grease is generally applied on the raceways 5, 6, 7, and 8 in order to allow the balls 9 to smoothly roll and prevent the raceways 5, 6, 7, and 8 from being abraded. However, when the lubricant is contaminated by impurities, such as dust, that have arrived at the raceways 5, 6, 7, and 8, the endurance of the rails 2, 3, and 4 is rapidly reduced. In addition, when the slide apparatus is repeatedly withdrawn and retracted, the lubricant is pushed by the balls 9, thereby leaking from the raceways 5, 6, 7, and 8. Consequently, the other portions of the rails 2, 3, and 4 are contaminated by the lubricant, and the amount of the lubricant performing a lubrication function becomes insufficient, such that the balls 9 or the raceways 5, 6, 7, and 8 are abraded. In order to overcome this problem, in the related art, lubricant is periodically applied on the raceways 5, 6, 7, and 8.
Furthermore, when wood chips, which are larger than dust, fall on the raceways 5, 6, 7, and 8, the wood chips may be caught between the balls 9 and the raceways 5, 6, 7, and 8, whereby the slide apparatus 1 may become inoperative.
In addition, in the slide apparatus 1, when the first movable rail 240 and the second movable rail 270 arrive at maximum withdrawal positions and maximum retraction positions during the withdrawal and retraction of the drawer, some balls 9 positioned at the leading end in the direction in which the first movable rail 240 and the second movable rail 270 move are caught by stoppers (not shown) provided on the fixed rail 210 and the first movable rail 240, whereby the first movable rail 240 and the second movable rail 270 move no more. When the drawer is manipulated with an excessively large amount of force during the withdrawal and retraction of the drawer, a large impact is applied to the ball retainer 100 in the maximum withdrawal point and the maximum retraction point of the drawer. As the ball retainer 100 has the shape of a thin plate, such an impact may cause the ball retainer 100 to move over the balls 9, such that the balls 9 are dislodged from the ball retainer 100, which is problematic.
Thus, it is required to provide a means for removing dust such that the operation of the slide apparatus is not influenced by dust occurring from the drawer in which the slide apparatus is disposed and protecting lubricant that enables the slide apparatus to smoothly roll and prevents the raceways from being abraded. In addition, there is great necessity for the ball retainer 100 able to reliably retain the balls 9 such that the balls 9 are not dislodged from the ball retainer 100 when a large impact is applied to the ball retainer due to an excessively large amount of force acting on the drawer during the withdrawal and retraction of the drawer.